When the daughter of our client experienced being taken out of her body into a lightbulb nearby, as witnessed by her brother, was this done by spirit meddlers, extraterrestrial spirits, or physical extraterrestrials?

This was done by extraterrestrial spirits who enticed her consciousness and then, in effect, punished her for following their lead by trapping her within a lightbulb, which they knew she would find terrifying and, of course, with her brother witnessing this it terrified him as well. This shows the mentality of the extraterrestrial beings you are dealing with, that they are quite savage, ruthless, and relentless in carrying out harassment and worse, against helpless human beings, including infants and children.